I think that all things which evoke discipline: study, and our duties to men and to the commonwealth, war, and personal hardship, and even the need for subsistence, ought to be greeted by us with profound gratitude, for only through them can we attain to the least detachment; and only so can we know peace.

[About the great synthesis of atomic physics in the 1920s:] It was a heroic time. It was not the doing of any one man; it involved the collaboration of scores of scientists from many different lands. But from the first to last the deeply creative, subtle and critical spirit of Niels Bohr guided, restrained, deepened and finally transmuted the enterprise.

It is not possible to be a scientist unless you believe that it is good to learn... that it is of the highest value to share your knowledge... with anyone who is interested... that the knowledge of the world, and the power which this gives, is a thing which is of intrinsic value to humanity

I remembered the line from the Hindu scripture, the Bhagavad-Gita... "Now I am become Death, the destroyer of worlds." I suppose we all thought that, one way or another.

We do not believe any group of men adequate enough or wise enough to operate without scrutiny or without criticism. We know that the only way to avoid error is to detect it, that the only way to detect it is to be free to inquire. We know that in secrecy error, undetected, will flourish and subvert.

Both the man of science and the man of art live always at the edge of mystery, surrounded by it. Both, as a measure of their creation, have always had to do with the harmonization of what is new with what is familiar, with the balance between novelty and synthesis, with the struggle to make partial order in total chaos.... This cannot be an easy life.

In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.